Apparatus and method for internally cooling a plastic tubular film bubble
CA 1102062 A · Owner: Union Carbide Corporation · Inventors: Alderfer, Richard B.; Scheibner, Gerald H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus and method for internally cooling extruded tubular film produced from film-forming polymers such as polyethylene, polypropylene and the like. Film slitting means are provided for continuously slitting the extruded film to provide at least one slitted opening therein. A diffuser is disposed in the extruded film tube and is supplied with gaseous coolant through the slitted opening and delivered therefrom to the interior surface of the extruded film tube, whereby gaseous coolant passes into contact with the interior surface of the tube for cooling thereof and thereafter is withdrawn through the slitted opening in the extruded film tube. S P E C I F I C A T I O N 1.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 2, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 2, 1998.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.